Governor for pressure-fluid-operated tools



Aug.` 30, 1927-. 1,640,620

E; H. SHAFF GGVERNOR FOR PRESSURE FLUID OPERATED TOOLS Filed Aug. 29, 1925 lfm/MMM' wwf Patented Aug. 30, 1927.

uNiTEn STATES PATENT OFFICE.

ERNEST H. SHAFF, OF GRAND HAVEN, IYIICHIGAN,-ASSIGNOR TO WILLIAM H. KELLER,

INC., OF GRAND HAVEN, MICHIGAN, A CORPORATION OF MICHIGAN.

GOVERNOR FOR FRESUItEMFLUID'OPEBATED TOOLS.

Application filled. August 29, 1925. Serial No. 53,241.

rIhe invention relates generally to automatic governors and more particularly to governors for pressure fluid operated tools, such as pneumatic grinders, drills, etc.

In the pressure fluid supply line of a tool of y this type it is desirable `to, have an automatic governor which will pass arelatively small quantity of pressure fluid to the tool when the tool is idling7 or running light, thereby preventing excessive speed of the tool and waste of pressurerfluid; but which, upon `application of a load to the tool automatically will pass relatively larger quantitiesof pressure fluid as the load increases.

It is t-he general vobjectfof the invention to provide anew and improved governor of simple construction which rwill afford such control for a pressure fluid operated tool.

In order that' a governor of this type shall operate efiiciently it is necessary that the internal mechanism, which is normallyin contact with the pressure fluid, be composed of materials lunaffected by steam, oil or other fluidsordinarily encountered in devices of this kind and be of such construction as to be free to operate even though foreign matter should collect thereon.: It is another object of the invention to produce a governor which incorporates anactuating element embodying these features.

Cork is practically unaffected by such fluids. A block of cork, if compressed lon-l gitudinally until its length lis reduced to about one-tenth ofthe original length does not increase -appreciably in cross section.`

Upon release the cork will expand longitudinally to `about three-quartersof its orig-V inallength with the new characteristic that it is softer` than before and resilient but longitudinally only, that is, aftersuch treatment the cork may be compressed longitudinally under fairly low pressure while it re-l `tains its original rigidity'transversely. y It is possible to repeatedly compress and release the cork manytimes withoutlosing this resiliency. If placed in a container and sub-v in a transverse direction. Y

It is a further object of the invention to Yincorporate a block of cork as the actuating element of a lvalve'in a governor for pres 'sure Huid operated tools, the cork having first heen treated as described above. .In pursuance of the foregoing objectsfa I aim'to provide an improved governor comprising a casing having a pressure fluid passagev therethrough controlled by a valve which. has an actuating element ,of cork. treated in this manner, the valve being arranged normally to permit a relatively small amount of pressure fluidto pass through the casing, but, uponincrease of back pressure in the vvalve 'chamber such as occurs when a load is applied to the tool, being adapted automatically to permit increasing quantities of pressure fluid to flow as the load increases. L

Furtherobjects and advantages will become apparent as the description proceeds.

In the drawings: v v

Figure 1 is a central longitudinal sectiony illustrating one form of the invention. i

Fig. 2 lis a central longitudinal section of the valve and mounting therefor.

Fig. 3 is a view looking at the left end of Fig. l.

' Fig.v 4: is a View looking at the left end of Fig. 2.

Fig. 5 is a sectional view along line 5 5 of Fig. l. y' n Vhile I have shown inthe drawings and will'herein describe in detail the preferred embodiment of my invention, it is to be understood that I do not thereby intend'to j limit the invention to the specific form dis- In the exemplary form illustrated, the

governor lcomprises, a casing l adapted to be connected in a pressure fluid supply line (not shown), this casing being herein shown as composedof two` sections 2 and Shaving abut-ting shoulders 4 and 5 held in air-tight engagementby means of the screw-threaded portions 6 and 7 of the sections. The sec-V tion 2 is'k also screw threaded at f8V andy the,

section 3 at` 9 to readily permit coupling of thel casing in a pressure fluid supply line.

As viewed in Fig. 1, the right hand end 3a is the normal intake end of the governor. At this end a hollow cup-shaped plug 10 is suitably mounted in thecasing section 3, 'the plug herein shown being a Vpress fit. This plu@ hask openings 11 in the wall thereof to esta lish communication between the chamber Hand the. intake end ythe gVIIlOi erating this valve a block of cork`16 treatedA as hereinbefore described is mounted as by means of a suitable cement, With one end in the valve member 13 and the other end in a cup-shaped portion 17 of a valve mounting` member 1'8f VThis member 18 comprises a threaded flange portion 19, in engagement With the threaded portion 7 of the casing section 3 to permit of longitudinal 4adjustment therein, and the cup-shaped portion 17 hereinbeforementioned. ln the flangedportion 19 are provided passageways 2O to establish communication between the valve chamber 12 and the outlet bore 21 of the casing section 2.

In thefform illustrated the valve member 13 has a vent- 22 therethrough toieq-ualize, 'at all times, the pressure in the chamber formed between the said valve member and the plug 15 andthe pressure in the valve chamber 12. The Wall 14 is adapted to limit the movement .ofthevalve in closing the openings 11, so that With the surface of the Wall contactingthe plug 10 a sufficient portion of the openings 11 remains uncovered to permit thepassage of pressure fluid to operate a tool when idling. The mounting member 418 has a disanietrical groove 23 therein adaptedto be engaged by a screvv driver to facilitate adjustment of theentire valve structure longitudinally of the casing when it isdesred to adjustthe Inormal position of the valveor to increase or `decreaseithe pressure vWhich the lvalve 13 normally exerts on the plug E1 0.

lin operation, With the end 3 ofithe governor Vconnected, to the ypressure fluid supply line and the other end connectedtoa pressureffluid oper-ated tool, the, Smallamount of pressure fluidl permitted to passl through the openings y11 -ivith the valve 13 in its closed position is predetermined and is designed to operate the tool lat anidling speed, i. e., a safe speed Withpno load on the tool. Under such vconditions the pressure required tooperate the ltoolis very: Smallso that the pressure inthe valve. chamber 1 2 is' butl slightly aboveatmospheric. VVhena loadis applied to the tool thespeed of the tooldecreases and the Pressure Yin the valve chamber iincreases until it V is suflicient to ,compress the cork 16 longitudinallyto operate the valve 113 ,and thereby permit .increased Aquantities of pressure 'fluid to pass `through the gov ernor.

-From the foregoing it will be apparent tliatlhave,provided agovernor for pressurefluid Qperated-.tools of simple and improved construction wherein there are no closely fitted sliding surfaces to be affected by deposits of foreign matter, which has a valve actuating'device that is unaffected by moisture, oils, etc., and which automaticallv vvill oermit increasino` uantities ofV pressurefluid to flow through the governor to a tool as the load upon the'tool increases.

I claim asmy invention:

1. A governor of the character described "having, in combination, a casing, a cupshaped plugmounted at one end thereof and having an aperturetherein to permit flow of pressure iluid therethrough, a valve y guided by Asaid plug and normally tending to close said aperture, means to operate said valve comprising a longitudinally ,resilient Y ,the pressure of the pressure fluid to open saidV valve, and means for adjusting the normal position ofisaid valve.

A governor of the character described having, in combination, a casing having a 4passage ,to permit flowof pressure fluid therethrough and .a valve device adapted normally to restrict said passage, said valve device comprising a block of corlrprevious- Vly compressed longitudinally to approximately one-tenth its orioinallength.

1. A;governor of the character described having,` in combination, `a casing and a lon-V gitudinally resilient cork mounted thereinV and carrying a valve to control the flow of fluid through the casing.

5. A governor of the character describedy having, in combination, a casing and means therein carrying a valve to control the flow of'fluid through the casing, said` means com- ,prising a solid block of material compressi- 'ble longitudinally but vrelatively non-comrressible .transversely V'In testimony `\vhei 'eof, l have hereunto affixed my signature.

YERNEST H- SHAFF 

